1,720,974 research outputs found
P2012: Building an ecosystem for a scalable, modular and high-efficiency embedded computing accelerator
No full textP2012 is an area- and power-efficient many-core
computing fabric based on multiple globally asynchronous,
locally synchronous (GALS) clusters supporting aggressive finegrained
power, reliability and variability management. Clusters
feature up to 16 processors and one control processor with
independent instruction streams sharing a multi-banked L1 data
memory, a multi-channel DMA engine, and specialized hardware
for synchronization and scheduling. P2012 achieves extreme area
and energy efficiency by supporting domain-specific acceleration
at the processor and cluster level through the addition of
dedicated HW IPs. P2012 can run standard OpenCL and
OpenMP parallel codes well as proprietary Native Programming
Model (NPM) SW components that provide the highest level of
control on application-to-resource mapping. In Q3 2011 the
P2012 SW Development Kit (SDK) has been made available to a
community of R&D users; it includes full OpenCL and NPM
development environments. The first P2012 SoC prototype in
28nm CMOS will sample in Q4 2012, featuring four clusters and
delivering 80GOPS (with single precision floating point support)
in 15.2mm2 with 2W power consumption
A Comparision of Back-Off and Ternary Tree Collision Resolution Algorithms in HFC Access Networks
No full textSydney, Australia
Wireless adaptive video streaming by real-time channel estimation and video transcoding
No full textA system composed by an MPEG-2 video transcoder to change bitrate, frame rate and frame size and a Cross Layer Controller gathering information from physical, MAC, driver, RTCP layers, calculating instantaneous network throughput, to optimize real-time adaptive a/v streaming over 802.11. © 2005 IEEE
A large scale SHM system: A case study on pre-stressed bridge and cloud architecture
Full text linkIn recent decades, external prestressing is increasingly being used especially in motorway and railway bridge structures due to the substantial savings in terms of construction time and costs. In such systems, internal and external steel tendons work together with concrete elements to withstand external actions. This means that the deterioration or failure of these elements reduces structural safety in a meaningful way. Real time monitoring of prestressing tendons can provide useful information on the health of the bridge under service loads, detecting possible fatigue, corrosion and damage/deterioration processes. However, most of the currently used structural monitoring systems are rather expensive and time consuming to install. Although many papers address high density sensing as the proper solution thanks to the “internet of things” tool, both for hardware and software, there are not so many applications in which this approach is really put into service. This paper describes the application of MEMS accelerometers in a high performance and cost-effective SHM system for bridge structures. In particular, data from a real time monitoring system installed in a box section composite highway bridge are presented. The external tendons of this bridge have been instrumented with a total number of 88 triaxial accelerometers. Changes in the dynamic characteristics of the monitored elements have been analyzed by detecting the shift in tendons’ dynamic behavior. The main challenge was collecting a huge amount of data and find a way to properly process them, not requiring the operator’s direct action, unless the observed situation is out of the “normal” scenario. For this purpose, simple but easy-to-implement specific data processing algorithms have been tested in order to check the real feasibility of such a SHM system first, and then to analyze the collected sensor data and provide an efficient real time damage detection
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
GORA: Goodput Optimal Rate Adaptation for 802.11 using Medium Status Estimation
No full textRate adaptation for 802.11 has been deeply investigated in the past, but the problem of achieving optimal rate adaptation with respect not only to channel-related errors but also to contention-related issues (i.e., collisions and variations in medium access times) is still unsolved. In this paper we address this issue by proposing (1) a practical definition of the medium status in a multi-user 802.11 scenario in terms of channel errors, MAC collisions and packet service times, and a method for its estimation based on measurements; (2) an analytical model of the goodput performance as a function of the Medium Status; (3) a rate adaptation algorithm, called goodput optimal rate adaptation (GORA), which is based on this model. Unlike other rate adaptation schemes proposed in literature, which require either modifications to the IEEE 802.11 standard or cooperation among nodes, GORA is totally stand-alone and standard compliant. In fact, the Medium Status Estimation used by GORA is obtained by using standard MAC counters that are commonly collected by commercial MAC drivers, and no explicit interactions with the other devices in the network is required. Therefore, GORA offers the advantage of being readily deployable on real devices. The performance of GORA is evaluated through NS2 simulations which reveal that, as expected, GORA outperforms other well- known rate adaptation algorithms in several scenarios and can be used as a new reference benchmark
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
APOS: Adaptive Parameters Optimization Scheme for Voice over IEEE 802.11g
No full textIn this paper we present APOS, a method for dynamically adapting the parameters of IEEE 802.11 g to the estimated system state, with the aim of enhancing the quality of a voice communication between a mobile station and a remote peer node. The system state is estimated based on a number of counters that are collected by the MAC layer of the mobile station, regarding the number of successful and unsuccessful transmission/reception events, channel busy periods and idle slots. These statistics are processed to estimate the collision probability and the signal to noise ratio at the receiver side. Hence, a mathematical model is used to get the expected end-to-end network performance in terms of throughput, delay and packet error rate, for different settings of some PHY and MAC parameters, such as the modulation/coding scheme and the retransmission limit. The setting that is estimated to maximize the quality of service for the end user is then selected. Unlike other optimization mechanisms proposed in literature, APOS is totally stand-alone and standard compliant. In fact, APOS makes use of local information that can be collected from the Network Interface Card, and no explicit interactions with the other devices in the network is required
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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